refactor(tests): enhance test infrastructure with library/collection helpers

- Add LibraryTestData struct to TestDeviceSetup
- Implement CreateLibrary() for proper library creation in tests
- Implement CreateCollection() for test collection support
- Improve test isolation with dedicated library creation

This provides a more robust foundation for integration tests that need
proper library management support.

cmd/server/main.go

@@ -120,7 +120,6 @@ func main() {
 	// NEW: Create refactored handlers
 	collectionHandler := handlers.NewCollectionHandler(queries, connManager)
 	mediaHandler := handlers.NewMediaHandler(queries, libraryService, worker)
-	searchHandler := handlers.NewSearchHandler(queries)
 	matchingHandler := handlers.NewMatchingHandler(queries, connManager)
 
 	e := echo.New()
@@ -162,7 +161,6 @@ func main() {
 		LibraryHandler:        libraryHandler,
 		DeviceHandler:         deviceHandler,
 		MediaHandler:          mediaHandler,
-		SearchHandler:         searchHandler,
 		MatchingHandler:       matchingHandler,
 		KOReaderHandler:       koreaderHandler,
 		WSHandler:             wsHandler,